Ways to winterize your windows

By Mary Jo Bowling Courtesy Sunset.com

How to make older windows more energy efficient--from films to shades

Many older windows need help to become more energy efficient. Here's what you can do to improve their energy performance, short of replacement or the addition of storm windows.

* CAULK around the frame to seal any cracks or small holes. Use other material, like weather-stripping, to block cracks and gaps around the moving parts of the window, such as the sash. According to Joe Wiehagen, research engineer at the National Association of Home Builders Research Center, "The energy efficiency you gain will more than make up for the cost and effort."

* APPLY LOW-E FILMS TO EXISTING WINDOWS.

They block heat, keeping it inside in the winter and outside during the summer. They require care in application to avoid bubbling or wrinkling. For the best performance, be certain to follow the manufacturer's instructions; from around $5 per square foot.

* USE MULTILAYERED OR COMBINED TREATMENTS TO INHIBIT HEAT LOSS. Dean Lerch of home-furnishing retailer Smith and Noble compares layering window treatments to dressing for winter weather: The more layers you have, the warmer you will be. He suggests pairing vinyl-backed curtains with blinds. Lerch likes vinyl because it doesn't transmit heat and is heavier than other backings. Another approach is to use heavy draperies, placing sheer draperies next to the glass.

* HANG WALL-LENGTH DRAPERIES to prevent losing heat from either the top or the bottom of the window treatment. Making it wider than the window will also stop convective currents that bring cool air into the room.

* LININGS WILL HELP make curtains and shades more energy efficient. Many linings come in cotton and cotton blends, but you can also get them in insulating blackout cloth, an acrylic foam-coated fabric now standard in hotel rooms. Available at fabric stores, it comes in a variety of colors and styles appropriate for residential uses; from about $6 per yard. Drapery liners are available that hook onto existing window treatments and roller blinds. Draperies and window molding can be fitted with magnets for a tighter fit.

* INSTALL THERMAL SHADES, which are filled with insulating air pockets to create a sort of blanket. From the side, some thermal shades resemble honeycombs. Look for a thermal shade's R-value, which measures a resistance to heat flow. A higher R-value means that the material is more energy efficient. Thermal shades run $350 to $500 and up for a 48- by 60-inch window.

GOOD ADVICE: According to Department of Energy studies, consumers with older windows can trim 5 to 10 percent off their energy bill by simply closing shades or drapes when the sun isn't coming through the window.